Research for the relationship between threshold of viability and fetal lung structure, and mechanism of fetal hypoplastic lungs

20世纪90年代，在日本和西方国家，随着表面活性物质治疗、以高频振荡通气（HFO）为代表的机械通气新方法和产前类固醇治疗等新治疗方法的普及，极早产儿（ELBW）和极早产儿（VLBW）的存活率有所提高。日本儿科学会新生儿委员会对ELBW和VLBW的结局进行了全国范围的调查，以报告日本NICU的现状和新生儿死亡率（每5年一次）。出生时体重不足1 000克的婴儿死亡率在过去20年中显著下降，从1980年的55.3%和1990年的28.2%下降到2000年的17.8%。有鉴于此，日本厚生劳动省于1991年1月将《产妇保护法》中的生存能力阈值的定义从妊娠24周改为妊娠22周。在这一变化之后，日本的产科医生越来越多地在妊娠22-23周时进行干预。迄今为止，对妊娠22周出生的婴儿进行重症监护已经15年，日本仍在继续努力改善此类婴儿的预后。本研究的目的如下：1.验证妊娠22周作为存活阈值的可行性1）分析妊娠21周流产胎儿的肺成熟2）全国范围内妊娠22-23周出生的短期预后调查3）全国范围内出生体重小于500 g的婴儿的短期预后调查4）早产儿和足月儿尿类固醇谱分析2.实验分析1）宫内感染与体外KL-6产生的关系2）乳铁蛋白预防假性肺炎

In Japan as well as western countries, the survival rate of extremely premature infants (ELBW) and very premature infants (VLBW) improved in the 1990s with the spread of new treatment methods such as surfactant therapy, new methods of mechanical ventilation represented by high frequency oscillatory ventilation (HFO), and prenatal steroid therapy. The Committee on Newborn Infants, Japan Society of Pediatrics has performed nation-wide surveys on the outcomes of ELBW and VLBW for reports on the current status of NICU and neonatal mortality in Japan at 5-year intervals. The mortality rate of infants weighing less than 1,000 g at birth significantly declined in the previous two decades from 55.3% in 1980 and 28.2% in 1990 to 17.8% in 2000. In view of this, the Ministry of Health, Labour and Welfare of the Japanese government changed the definition of the threshold of viability in the Maternal Protection Law from 24 weeks of gestation to 22 weeks of gestation in January, 1991. After this change, neonatologists in Japan have increasingly intervened in deliveries at 22-23 weeks' of gestation. To date, 15years have passed since intensive care for infants born at 22weeks' gestation was undertaken and efforts to improve the prognosis of such infants are continuing in Japan. The purpose of this project was as follows :1.For test to validate 22 weeks gestation as threshold of viability1)the analysis lung maturation of fetuses aborted at 21 weeks gestation2)nation wide survey of short term prognosis born at 22-23 weeks gestation3)nation wide survey of short term outcome of infants born weighing less than 500 grams4)the analysis of urine steroid profile of preterm and term infants2.experimental analysis1)the relationship between intrauterine infection and KL-6 production in vitro2)intaratracheal administration of lactoferrin to prevent pseudomonas pneumonia